Answer:
(10x - 5) square units.
Step-by-step explanation:
Let the lengths of equal sides be x units.
Hence, AB + AD + DC = x + x + x = 3x
Therefore, BC = 3x - 2

Answer:
I say its number 2
Step-by-step explanation:
Prime Factors of 60: 2,3, and 5
Prime Factors of 140: 2,5 and 7
All mental math no work needed.
Distance to travel = 20 m.
Let us determine the time, t, that each participant took to complete 20 m.
Barbara:
Average speed = (3 m)/(2 s) = 1.5 m/s
t = 20/1.5 = 13.3 s
Mark:
t = 5 s
Carlos:
y = x + 1
where
y = 20 m
x = time, t
Therefore
t =x = y - 1 = 20 - 1 = 19 s
Summary:
Barbara: 13.3 s
Mark: 5 s
Carlos: 19 s
Answer:
The winner is Mark